Created a simple test for the mTLS scenario

This test does nothing more than create a project with a readme.

qa/qa/specs/features/api/3_create/gitaly/gitaly_mtls_spec.rb

+# frozen_string_literal: true
+
+module QA
+  RSpec.describe 'Create' do
+    context 'Gitaly', :orchestrated, :mtls do
+      describe 'Using mTLS' do
+        let(:intial_commit_message) { 'Initial commit' }
+        let(:first_added_commit_message) { 'commit over git' }
+        let(:second_added_commit_message) { 'commit over api' }
+
+        it 'pushes to gitaly', testcase: 'https://gitlab.com/gitlab-org/quality/testcases/-/issues/1118' do
+          project = Resource::Project.fabricate! do |project|
+            project.name = "mTLS"
+            project.initialize_with_readme = true
+          end
+
+          Resource::Repository::ProjectPush.fabricate! do |push|
+            push.project = project
+            push.new_branch = false
+            push.commit_message = first_added_commit_message
+            push.file_content = 'First commit'
+          end
+
+          Resource::Repository::Commit.fabricate_via_api! do |commit|
+            commit.project = project
+            commit.commit_message = second_added_commit_message
+            commit.add_files([
+              {
+                file_path: "file-#{SecureRandom.hex(8)}",
+                content: 'Second commit'
+              }
+            ])
+          end
+
+          expect(project.commits.map { |commit| commit[:message].chomp })
+            .to include(intial_commit_message)
+            .and include(first_added_commit_message)
+            .and include(second_added_commit_message)
+        end
+      end
+    end
+  end
+end